JP3967536B2 - Internal combustion engine having variable valve mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention provides an intake valve, an exhaust valve,The opening and closing time ofThe present invention relates to an internal combustion engine having a variable valve mechanism that can be arbitrarily changed, and more particularly to a technique for suitably generating an intake pipe negative pressure in an intake passage of the internal combustion engine.
[0002]
[Prior art]
  In recent years, an internal combustion engine mounted on an automobile or the like has an intake valve and an exhaust valve for the purpose of improving net thermal efficiency, improving exhaust emission, or reducing fuel consumption.The opening and closing time ofDevelopment of an internal combustion engine having a variable valve mechanism that can be arbitrarily changed is underway.
[0003]
  As a variable valve mechanism, for example, an internal combustion engine provided with an intake / exhaust valve that is driven to open and close by electromagnetic force, a so-called electromagnetically driven valve mechanism is known. In an internal combustion engine equipped with such an electromagnetically driven valve mechanism, it is not necessary to open and close the intake / exhaust valve using the rotational force of the engine output shaft, thus preventing mechanical loss due to the drive of the intake / exhaust valve. Is done. Furthermore, in an internal combustion engine equipped with an electromagnetically driven valve mechanism, it is possible to arbitrarily change the valve opening time and opening / closing timing of the intake / exhaust valves, so the intake air amount of each cylinder can be reduced without using a throttle valve. It is possible to realize so-called non-throttle operation control, and as a result, it is possible to suppress the pump loss of the internal combustion engine caused by the throttle valve.
[0004]
  By the way, in the internal combustion engine controlled by the non-throttle operation, there is a problem that the pump loss of the internal combustion engine hardly occurs, so that the combustion chamber of the internal combustion engine does not become negative pressure when the vehicle is decelerated, and the effectiveness of the engine brake is weakened. .
[0005]
  On the other hand, conventionally, a control method for an internal combustion engine as described in JP-A-10-331671 has been proposed. In the internal combustion engine control method described in this publication, the pump loss of the internal combustion engine is reduced in an internal combustion engine in which the intake valve and the exhaust valve are configured by electromagnetically driven valves and non-throttle operation control is performed using these electromagnetically driven valves. By controlling the electromagnetically driven valve so as to increase, a negative pressure is generated in the cylinder of the internal combustion engine, thereby increasing the effectiveness of the engine brake.
[0006]
[Problems to be solved by the invention]
  By the way, in vehicles equipped with an internal combustion engine, BurningEvaporative fuel for combustion and processing of evaporative fuel generated in a fuel tank in an internal combustion engineThe reflux mechanismSome are provided.
[0007]
  However, like the control method of the conventional internal combustion engine described above,When performing non-throttle operation controlIn the method of increasing the pump loss of the internal combustion engine without using the throttle valve, it is difficult to generate the intake pipe negative pressure in the intake passage,Evaporative fuel recirculation mechanismThere is a problem that the intake pipe negative pressure related to the operation cannot be secured.
[0008]
  The present invention has been made in view of various circumstances as described above, and includes an intake valve, an exhaust valve,The opening and closing time ofA technology that can secure an intake pipe negative pressure related to the operation of the evaporative fuel recirculation mechanism in an internal combustion engine that includes a variable valve mechanism that can be arbitrarily changed, and an evaporative fuel recirculation mechanism that performs non-throttle operation control The purpose is to provide.
[0009]
[Means for Solving the Problems]
  The present invention employs the following means in order to solve the above-described problems.
  That is, an internal combustion engine having a variable valve mechanism according to the present invention includes an intake valve and an exhaust valve of an internal combustion engine.The opening and closing time ofAn internal combustion engine having an adjustable variable valve mechanism, wherein a throttle valve for adjusting a flow rate of intake air flowing in the intake passage, and an evaporative fuel generated in a fuel tank for the intake air downstream of the throttle valve An evaporative fuel recirculation mechanism that recirculates to the passage, non-throttle operation control execution means that executes non-throttle operation control when the operation state of the internal combustion engine is in a predetermined operation region, and the non-throttle operation control during execution of the non-throttle operation control Throttle valve control means for closing the throttle valve by a predetermined amount when the evaporated fuel recirculation mechanism needs to be operated, and when the throttle valve control means closes the throttle valve by a predetermined amount, A valve mechanism control means for controlling the variable valve mechanism so as to increase the intake efficiency of each cylinder so as to suppress a change in the intake air amount;When the evaporated fuel recirculation mechanism is operated, a required evaporated fuel amount calculating means for calculating a required evaporated fuel amount that is an amount of evaporated fuel to be recirculated to the intake passage, and the evaporated fuel of the required evaporated fuel amount is supplied to the intake passage. Target intake pipe negative pressure calculating means for calculating a target intake pipe negative pressure that is a minimum intake pipe negative pressure required for recirculation to the engine, and a target throttle opening of the throttle valve based on the target intake pipe negative pressure. Target throttle opening determining means for determining the degree, and target intake air amount setting means for detecting the intake air amount at the time of operating the evaporated fuel recirculation mechanism and setting the detected intake air amount as the target intake air amount And target opening / closing timing determining means for determining the target opening / closing timing of the intake valve and the exhaust valve using the target throttle valve opening and the target intake air amount as parameters,WithWhen it becomes necessary to operate the evaporated fuel recirculation mechanism during execution of the non-throttle operation control, the throttle valve control means gradually closes the throttle valve opening to the target throttle opening, At the same time, the valve mechanism control means controls the variable valve mechanism to gradually change the opening / closing timing of the intake valve and the exhaust valve until the target opening / closing timing.It is characterized by that.
[0010]
  In the internal combustion engine having the variable valve mechanism configured as described above, when the operation state of the internal combustion engine is in a predetermined operation region (for example, a low and medium load operation region),Non-throttle operation control execution meansPerforms a so-called non-throttle operation control in which the intake valve of the internal combustion engine is adjusted by controlling the variable valve mechanism while holding the throttle valve at a predetermined opening (for example, an opening that is substantially fully open). When the operating state of the internal combustion engine is in a predetermined operating range, in other words,Non-throttle operation control execution meansWhen the non-throttle operation control is executed byWhen evaporative fuel recirculation mechanism needs to be activatedThe throttle valve control means closes the throttle valve by a predetermined amount from the predetermined opening. In this case, since intake pipe negative pressure is generated in the intake passage downstream of the throttle valve,Even when the non-throttle operation control is being executed, the intake pipe negative pressure related to the operation of the evaporated fuel recirculation mechanism can be secured.
[0011]
  Also aboveIn the internal combustion engine having the variable valve mechanism configured as described above,Non-throttle operation control execution meansWhen non-throttle operation control is executed byWhen evaporative fuel recirculation mechanism needs to be activatedThe throttle valve control means closes the throttle valve by a predetermined amount from the predetermined opening, and the valve mechanism control meansTo increase the intake efficiency of each cylinder to suppress changes in the intake air amount of the internal combustion engineThe variable valve mechanism will be controlled. In this case, without changing the intake air amount of the internal combustion engine,It is possible to ensure the intake pipe negative pressure related to the operation of the evaporated fuel recirculation mechanism.
[0012]
  The variable valve mechanism according to the present invention includes an electromagnetically driven valve mechanism that opens and closes an intake valve and / or an exhaust valve using electromagnetic force, and an open / close drive that opens and closes an intake valve and exhaust valve using hydraulic pressure. A hydraulically driven valve mechanism that can be used to change the rotational phase of the camshaft relative to the crankshaft in an internal combustion engine having a camshaft that uses the rotational force of the crankshaft to open and close the intake and exhaust valves. Examples thereof include a variable valve mechanism or a variable valve mechanism that is a combination of the above-described mechanisms as appropriate.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, a specific embodiment of an internal combustion engine having a variable valve mechanism according to the present invention will be described with reference to the drawings.
[0014]
  ThisHere, as an example of the variable valve mechanism according to the present invention, an electromagnetically driven valve mechanism that opens and closes an intake valve and an exhaust valve using electromagnetic force is given as an example.TheoryLight up.
[0015]
  Figure1These are figures which show schematic structure of the internal combustion engine which concerns on this Embodiment, and its intake-exhaust system. Figure1The internal combustion engine 1 shown in FIG. 1 is a water-cooled four-stroke cycle gasoline engine having four cylinders 21.
[0016]
  The internal combustion engine 1 includes a cylinder block 1b in which four cylinders 21 and a cooling water channel 1c are formed, and a cylinder head 1a fixed to the upper portion of the cylinder block 1b.
[0017]
  A crankshaft 23 as an engine output shaft is rotatably supported on the cylinder block 1b. The crankshaft 23 is connected to pistons 22 slidably loaded in the cylinders 21 via connecting rods. Yes.
[0018]
  A combustion chamber 24 surrounded by the top surface of the piston 22 and the wall surface of the cylinder head 1 a is formed above the piston 22 of each cylinder 21. An ignition plug 25 is attached to the cylinder head 1 a so as to face the combustion chamber 24 of each cylinder 21, and an igniter 25 a for applying a drive current to the ignition plug 25 is connected to the ignition plug 25. .
[0019]
  Two open ends of the intake port 26 and two open ends of the exhaust port 27 are formed at a portion of the cylinder head 1a facing the combustion chamber 24 of each cylinder 21. The cylinder head 1a is provided with an intake valve 28 that opens and closes each open end of the intake port 26 and an exhaust valve 29 that opens and closes each open end of the exhaust port 27 so as to freely advance and retract.
[0020]
  The cylinder head 1a includes an electromagnetic drive mechanism 30 (hereinafter referred to as an intake-side electromagnetic drive mechanism 30) that drives the intake valve 28 to advance and retreat using electromagnetic force generated when an excitation current is applied. The same number as 28 is provided. Each intake side electromagnetic drive mechanism 30 is electrically connected to a drive circuit 30a (hereinafter referred to as an intake side drive circuit 30a) for applying an excitation current to the intake side electromagnetic drive 30.
[0021]
  In the cylinder head 1a, an electromagnetic drive mechanism 31 (hereinafter referred to as an exhaust-side electromagnetic drive mechanism 31) that drives the exhaust valve 29 forward and backward using electromagnetic force generated when an excitation current is applied is provided in the exhaust valve. The same number as 29 is provided. Each exhaust side electromagnetic drive mechanism 31 is electrically connected to a drive circuit 31a (hereinafter referred to as an exhaust side drive circuit 31a) for applying an excitation current to the exhaust side electromagnetic drive mechanism 31.
[0022]
  The intake side electromagnetic drive mechanism 30, the intake side drive circuit 30a, the exhaust side electromagnetic drive mechanism 31, and the exhaust side drive circuit 31a described above correspond to the variable valve mechanism according to the present invention.
[0023]
  Here, specific configurations of the intake side electromagnetic drive mechanism 30 and the exhaust side electromagnetic drive mechanism 31 will be described. Since the intake side electromagnetic drive mechanism 30 and the exhaust side electromagnetic drive mechanism 31 have the same configuration, only the intake side electromagnetic drive mechanism 30 will be described as an example.
[0024]
  Figure2These are sectional views showing the configuration of the intake-side electromagnetic drive mechanism 30. Figure2The cylinder head 1a of the internal combustion engine 1 includes a lower head 10 fixed to the upper surface of the cylinder block 1b and an upper head 11 provided on the upper portion of the lower head 10.
[0025]
  The lower head 10 is formed with two intake ports 26 for each cylinder 21, and a valve seat 12 for seating a valve element 28 a of the intake valve 28 at the opening end of each intake port 26 on the combustion chamber 24 side. Is provided.
[0026]
  The lower head 10 is formed with a through hole having a circular cross section from the inner wall surface of each intake port 26 to the upper surface of the lower head 10, and a cylindrical valve guide 13 is inserted into the through hole. The valve shaft 28b of the intake valve 28 passes through the inner hole of the valve guide 13, and the valve shaft 28b is movable forward and backward in the axial direction.
[0027]
  A core mounting hole 14 having a circular cross section is provided in a portion of the upper head 11 having the same axis as the valve guide 13. The lower portion 14b of the core mounting hole 14 is formed with a larger diameter than the upper portion 14a. Hereinafter, the lower portion 14b of the core mounting hole 14 is referred to as a large diameter portion 14b, and the upper portion 14a of the core mounting hole 14 is referred to as a small diameter portion 14a.
[0028]
  An annular first core 301 and second core 302 made of a soft magnetic material are fitted in the small diameter portion 14a in series in the axial direction with a predetermined gap 303 interposed therebetween. The upper end of the first core 301 and the lower end of the second core 302 are respectively formed with a flange 301a and a flange 302a. The first core 301 is from above and the second core 302 is from below the core mounting holes. 14 and the flanges 301a and 302a abut against the edge of the core mounting hole 14, whereby the first core 301 and the second core 302 are positioned, and the gap 303 is held at a predetermined distance. It is like that.
[0029]
  A cylindrical upper cap 305 is provided above the first core 301. The upper cap 305 is fixed to the upper surface of the upper head 11 by passing a bolt 304 through a flange portion 305a formed at the lower end thereof. In this case, the lower end of the upper cap 305 including the flange portion 305 a is fixed in a state where the lower end of the upper cap 305 is in contact with the peripheral edge of the upper surface of the first core 301, and as a result, the first core 301 is fixed to the upper head 11. become.
[0030]
  On the other hand, a lower cap 307 made of an annular body having an outer diameter substantially the same diameter as the large-diameter portion 14 b of the core mounting hole 14 is provided at the lower portion of the second core 302. A bolt 307 passes through the lower cap 307, and is fixed to the downward step surface of the step portion of the small diameter portion 14a and the large diameter portion 14b by the bolt 307. In this case, the lower cap 307 is fixed in a state where it is in contact with the peripheral edge of the lower surface of the second core 302, and as a result, the second core 302 is fixed to the upper head 11.
[0031]
  A first electromagnetic coil 308 is gripped in the groove formed on the surface of the first core 301 on the gap 303 side, and the groove formed on the surface of the second core 302 on the surface of the gap 303 is The second electromagnetic coil 309 is gripped. At this time, the first electromagnetic coil 308 and the second electromagnetic coil 309 are arranged at positions facing each other with the gap 303 therebetween. The first and second electromagnetic coils 308 and 309 are electrically connected to the intake side drive circuit 30a described above.
[0032]
  An armature 311 made of an annular soft magnetic material having an outer diameter smaller than the inner diameter of the gap 303 is disposed in the gap 303. A columnar armature shaft 310 extending in the vertical direction along the axis of the armature 311 is fixed to the hollow portion of the armature 311. The armature shaft 310 has an upper end passing through the hollow portion of the first core 301 and reaching the upper cap 305 above it, and a lower end passing through the hollow portion of the second core 302 and a large diameter portion below it. 14b, and is held by the first core 301 and the second core 302 so as to be movable back and forth in the axial direction.
[0033]
  A disk-shaped upper retainer 312 is joined to the upper end of the armature shaft 310 extending into the upper cap 305, and an adjustment bolt 313 is screwed into the upper opening of the upper cap 305. An upper spring 314 is interposed between the upper retainer 312 and the adjusting bolt 313. A spring seat 315 having an outer diameter substantially the same as the inner diameter of the upper cap 305 is interposed on the contact surface between the adjustment bolt 313 and the upper spring 314.
[0034]
  On the other hand, the upper end portion of the valve shaft 28b of the intake valve 28 is in contact with the lower end portion of the armature shaft 310 extending into the large diameter portion 14b. A disc-shaped lower retainer 28 c is joined to the outer periphery of the upper end portion of the valve shaft 28 b, and a lower spring 316 is interposed between the lower surface of the lower retainer 28 c and the upper surface of the lower head 10.
[0035]
  In the intake-side electromagnetic drive mechanism 30 configured as described above, when no excitation current is applied from the intake-side drive circuit 30a to the first electromagnetic coil 308 and the second electromagnetic coil 309, the intake-side electromagnetic drive mechanism 30 starts from the upper spring 314. A biasing force in the downward direction (that is, the direction in which the intake valve 28 is opened) acts on the armature shaft 310 and the upward direction from the lower spring 316 to the intake valve 28 (that is, the intake valve 28 is closed). As a result, the armature shaft 310 and the intake valve 28 come into contact with each other and are elastically supported at a predetermined position, that is, held in a so-called neutral state.
[0036]
  The urging force of the upper spring 314 and the lower spring 316 is set so that the neutral position of the armature 311 coincides with an intermediate position between the first core 301 and the second core 302 in the gap 303. When the neutral position of the armature 311 is deviated from the above-described intermediate position due to initial tolerance or aging of components, the adjustment bolt 313 can be adjusted so that the neutral position of the armature 311 matches the above-described intermediate position. It has become.
[0037]
  The axial lengths of the armature shaft 310 and the valve shaft 28b are such that when the armature 311 is positioned at an intermediate position of the gap 303, the valve element 28a is fully opened and fully closed. And an intermediate position (hereinafter referred to as a middle open position).
[0038]
  In the intake-side electromagnetic drive mechanism 30 described above, when an excitation current is applied to the first electromagnetic coil 308 from the intake-side drive circuit 30a, the intake-side drive circuit 30a is connected between the first core 301, the first electromagnetic coil 308, and the armature 311. When an electromagnetic force is generated in a direction that displaces the armature 311 toward the first core 301, and an excitation current is applied to the second electromagnetic coil 309 from the intake side drive circuit 30 a, An electromagnetic force in a direction to displace the armature 311 toward the second core 302 is generated between the second electromagnetic coil 309 and the armature 311.
[0039]
  Therefore, in the intake side electromagnetic drive mechanism 30 described above, the excitation current from the intake side drive circuit 30a is alternately applied to the first electromagnetic coil 308 and the second electromagnetic coil 309, whereby the armature 311 moves forward and backward. As a result, the valve shaft 28b is driven to advance and retract, and at the same time, the valve body 28a is driven to open and close. At that time, it is possible to control the opening / closing timing of the intake valve 28 by changing the excitation current application timing and the magnitude of the excitation current to the first electromagnetic coil 308 and the second electromagnetic coil 309.
[0040]
  Further, a valve lift sensor 317 for detecting the displacement of the intake valve 28 is attached to the intake side electromagnetic drive mechanism 30 described above. The valve lift sensor 317 includes a disk-shaped target 317a attached to the upper surface of the apparator 312 and a gap sensor 317b attached to a portion of the adjustment bolt 313 facing the apparator 312.
[0041]
  In the valve lift sensor 317 configured as described above, the target 317a is integrally displaced with the armature 311 of the intake-side electromagnetic drive mechanism 30, and the gap sensor 317b is set at a distance between the gap sensor 317b and the target 317a. A corresponding electrical signal is output. At this time, the output signal value of the gap sensor 317b when the armature 311 is in the neutral state is stored in advance, and the difference between the output signal value and the output signal value of the gap sensor 317b at the present time is calculated, thereby obtaining the armature. 311 and the displacement of the intake valve 28 can be specified.
[0042]
  Where1Referring back to FIG. 2, the cylinder head 1a of the internal combustion engine 1 is connected to an intake branch pipe 33 formed of four branch pipes, and each branch pipe of the intake branch pipe 33 communicates with the intake port 26 of each cylinder 21. ing. A fuel injection valve 32 is attached to the cylinder head 1 a in the vicinity of the connection portion with the intake branch pipe 33 so that its injection hole faces the intake port 26.
[0043]
  The intake branch pipe 33 is connected to a surge tank 34 for suppressing intake pulsation. An intake pipe 35 is connected to the surge tank 34, and the intake pipe 35 is connected to an air cleaner box 36 for removing dust, dust and the like in the intake air.
[0044]
  An air flow meter 44 that outputs an electric signal corresponding to the mass of air flowing through the intake pipe 35 (intake air mass) is attached to the intake pipe 35. A throttle valve 39 for adjusting the flow rate of the intake air flowing through the intake pipe 35 is provided in a portion of the intake pipe 35 downstream of the air flow meter 44.
[0045]
  The throttle valve 39 is composed of a stepper motor or the like, and a throttle actuator 40 that opens and closes the throttle valve 39 according to the magnitude of applied power, and a throttle that outputs an electrical signal corresponding to the opening of the throttle valve 39. A position sensor 41 is attached.
[0046]
  On the other hand, an exhaust branch pipe 45 formed so that four branch pipes merge with one collecting pipe immediately downstream of the internal combustion engine 1 is connected to the cylinder head 1a of the internal combustion engine 1, and the exhaust branch pipes thereof. Each of the 45 branch pipes communicates with the exhaust port 27 of each cylinder 21.
[0047]
  The exhaust branch pipe 45 is connected to an exhaust pipe 47 through an exhaust purification catalyst 46, and the exhaust pipe 47 is connected downstream with a muffler (not shown). An air-fuel ratio sensor 48 that outputs an electric signal corresponding to the air-fuel ratio of the exhaust flowing through the exhaust branch pipe 45, in other words, the exhaust gas flowing into the exhaust purification catalyst 46, is attached to the exhaust branch pipe 45.
[0048]
  Here, as the above-described exhaust purification catalyst 46, for example, hydrocarbons (HC) contained in the exhaust when the air-fuel ratio of the exhaust flowing into the exhaust purification catalyst 46 is a predetermined air-fuel ratio in the vicinity of the theoretical air-fuel ratio. , A three-way catalyst for purifying carbon monoxide (CO) and nitrogen oxides (NOx), and a nitrogen oxide (NO) contained in the exhaust gas when the air-fuel ratio of the exhaust gas flowing into the exhaust gas purification catalyst 46 is a lean air-fuel ratio. NOx) is stored, and when the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst 46 is the stoichiometric air-fuel ratio or the rich air-fuel ratio, the storage reduction that reduces and purifies while releasing the stored nitrogen oxide (NOx). Type NOx catalyst, selective reduction type NOx that reduces and purifies nitrogen oxide (NOx) in the exhaust when the air-fuel ratio of the exhaust flowing into the exhaust purification catalyst 46 is in an oxygen excess state and a predetermined reducing agent is present Catalyst, or A catalyst formed by combining suitably various catalyst described above.
[0049]
  Next, the internal combustion engine 1Is steamedA fuel generation mechanism is also provided. The evaporative fuel processing mechanism includes a fuel tank 60, a charcoal canister 61 that temporarily stores evaporative fuel generated in the fuel tank 60, and evaporative fuel stored in the charcoal canister 61 downstream of the throttle valve 39 in the intake pipe 35. And a negative pressure introduction passage 65 that leads to the region.
[0050]
  The fuel tank 60 and the charcoal canister 61 are connected to each other through an evaporative fuel passage 62. A flow path in the evaporative fuel passage 62 is provided in the middle of the evaporative fuel passage 62 according to the pressure in the fuel tank 60. A tank internal pressure control valve 63 for opening and closing is attached. The tank internal pressure control valve 63 is configured by combining a positive pressure valve and a negative pressure valve, and the positive pressure valve opens when the pressure in the fuel tank 60 exceeds a first predetermined value due to an increase in evaporated fuel, and the negative pressure valve opens. The pressure valve opens when the pressure in the fuel tank 60 falls below a second predetermined value (<first predetermined value) due to a decrease in fuel.
[0051]
  In addition to the evaporated fuel passage 62 and the negative pressure introduction passage 65 described above, an atmospheric introduction passage 64 is connected to the charcoal canister 61. The end of the air introduction passage 64 is open to the atmosphere.
[0052]
  In the middle of the negative pressure introduction passage 65, a solenoid valve 67 is attached which is made of a stepping motor or the like and adjusts the flow rate in the negative pressure introduction passage 65.
[0053]
  The atmospheric introduction passage 64 and the negative pressure introduction passage 65 communicating with each other through the charcoal canister 61 form a purge passage (hereinafter, the charcoal canister 61, the atmospheric introduction passage 64, and the negative pressure introduction passage 65 are collectively referred to as a purge passage). 66). The purge passage 66 and the electromagnetic valve 67 correspond to the evaporated fuel recirculation means according to the present invention.
[0054]
  Next, the internal combustion engine 1 includes a crank position sensor 51 including a timing rotor 51a attached to an end of the crankshaft 23 and an electromagnetic pickup 51b attached to a cylinder block 1b in the vicinity of the timing rotor 51a, A water temperature sensor 52 attached to the cylinder block 1b is provided to detect the temperature of the cooling water flowing through the cooling water passage 1c formed inside.
[0055]
  The internal combustion engine 1 configured as described above is provided with an electronic control unit (ECU) 20 for controlling the operating state of the internal combustion engine 1.
[0056]
  A throttle position sensor 41, an air flow meter 44, an air-fuel ratio sensor 48, a crank position sensor 51, a water temperature sensor 52, and a valve lift sensor 317 are connected to the ECU 20 through electric wiring, and an accelerator installed in the vehicle interior. An accelerator position sensor 43 that outputs an electric signal corresponding to the operation amount of the pedal 42 is connected via an electric wiring, and an output signal of each sensor is input to the ECU 20.
[0057]
  The ECU 20 is connected to an igniter 25a, an intake-side drive circuit 30a, an exhaust-side drive circuit 31a, a fuel injection valve 32, a throttle actuator 40, an electromagnetic valve 67, and the like through electric wiring, and the ECU 20 outputs output signals of various sensors. It is possible to control the igniter 25a, the intake side drive circuit 30a, the exhaust side drive circuit 31a, the fuel injection valve 32, the throttle actuator 40, and the electromagnetic valve 67 using the values as parameters.
[0058]
  Here, the ECU 203As shown in FIG. 1, the CPU 401, the ROM 402, the RAM 403, the backup RAM 404, the input port 405, and the output port 406 are connected to each other by the bidirectional bus 400, and the A / D converter ( A / D) 407 is provided.
[0059]
  The A / D 407 includes a throttle position sensor 41, an accelerator position sensor 43, an air flow meter 44, an air-fuel ratio sensor 48, a water temperature sensor 52, a valve lift sensor 317, and other sensors that output analog signal format signals and electrical wiring. Connected through. The A / D 407 converts the output signal of each sensor described above from an analog signal format to a digital signal format, and transmits the converted signal to the input port 405.
[0060]
  The input port 405 includes a sensor that outputs an analog signal format signal, such as the throttle position sensor 41, the accelerator position sensor 43, the air flow meter 44, the air-fuel ratio sensor 48, the water temperature sensor 52, the valve lift sensor 317, etc. It is connected via an A / D 407 and is connected to a sensor that outputs a digital signal format signal, such as the crank position sensor 51. The input port 405 inputs output signals of various sensors directly or via the A / D 407 and transmits these output signals to the CPU 401 and the RAM 403 via the bidirectional bus 400.
[0061]
  The output port 406 is connected to the igniter 25a, the intake side drive circuit 30a, the exhaust side drive circuit 31a, the fuel injection valve 32, the throttle actuator 40, the electromagnetic valve 67, and the like through electrical wiring. The output port 406 inputs a control signal output from the CPU 401 via the bidirectional bus 400, and the control signal is sent to the igniter 25a, the intake side drive circuit 30a, the exhaust side drive circuit 31a, the fuel injection valve 32, and the throttle. It transmits to the actuator 40 or the electromagnetic valve 67.
[0062]
  The ROM 402 is a fuel injection amount control routine for determining the fuel injection amount, a fuel injection timing control routine for determining the fuel injection timing, an ignition timing control routine for determining the ignition timing, and an opening / closing timing of the intake valve 28. An intake valve opening / closing timing control routine for determining the exhaust valve 29, an exhaust valve opening / closing timing control routine for determining the opening / closing timing of the exhaust valve 29, and an intake side for determining the amount of excitation current to be applied to the intake side electromagnetic drive mechanism 30 Applications such as an excitation current control routine, an exhaust side excitation current amount control routine for determining the amount of excitation current to be applied to the exhaust side electromagnetic drive mechanism 31, and a throttle opening degree control routine for determining the opening degree of the throttle valve 39 In addition to programs, application programs such as purge control routines for purging evaporated fuel are stored. There. The ROM 402 stores various control maps in addition to the application programs as described above. The control map is, for example, a fuel injection amount control map showing the relationship between the operating state of the internal combustion engine 1 and the fuel injection amount, a fuel injection timing control map showing the relationship between the operating state of the internal combustion engine 1 and the fuel injection timing, and the internal combustion engine 1 is an ignition timing control map showing the relationship between the operating state and the ignition timing, an intake valve opening / closing timing control map showing the relationship between the operating state of the internal combustion engine 1 and the opening / closing timing of the intake valve 28, and the operating state and exhaust of the internal combustion engine 1. Exhaust valve opening / closing timing control map showing the relationship with the opening / closing timing of the valve 29, excitation showing the relationship between the operating state of the internal combustion engine 1 and the amount of excitation current to be applied to the intake side electromagnetic drive mechanism 30 and the exhaust side electromagnetic drive mechanism 31 Current amount control map, throttle opening degree control map showing the relationship between the operating state of the internal combustion engine 1 and the opening degree of the throttle valve 39, the state of the internal combustion engine 1, the fuel tank 33, or the charcoal canister 31 Required evaporation fuel amount control map showing the relationship between the amount of evaporated fuel to be purged and the amount of evaporated fuel to be purged (required evaporated fuel amount), or the opening degree of the electromagnetic valve 34 required to purge the required evaporated fuel amount and the required evaporated fuel amount A required duty ratio control map showing a relationship with (requested duty ratio).
[0063]
  The RAM 403 stores output signals of the sensors, calculation results of the CPU 401, and the like. The calculation result is, for example, the engine speed calculated based on the output signal of the crank position sensor 51. Data stored in the RAM 403 (data such as output signals of the sensors and calculation results of the CPU 401) is updated to the latest data every time the crank position sensor 51 outputs a pulse signal.
[0064]
  The backup RAM 404 is a nonvolatile memory that retains data even after the operation of the internal combustion engine 1 is stopped, and stores learning values and the like related to various controls.
[0065]
  The CPU 401 operates in accordance with an application program stored in the ROM 402, determines the operating state of the internal combustion engine 1 and the state of the charcoal canister 61 from the output signal of each sensor, determines the determined operating state and the state of the charcoal canister 61, and the respective states. From the control map, the fuel injection amount, the fuel injection timing, the throttle opening, the ignition timing, the opening / closing timing of the intake valve 28, the opening / closing timing of the exhaust valve 29, the duty ratio for controlling the electromagnetic valve 67, the fuel injection amount at the time of purge execution A correction amount and the like are calculated. Then, the CPU 42 outputs a control signal for the igniter 25a, the fuel injection valve 32, the throttle actuator 40, the intake side drive circuit 30a, the exhaust side drive circuit 31a, or the electromagnetic valve 67 based on the calculation result.
[0066]
  For example, the CPU 42 determines the operating state of the internal combustion engine 1 from the output signal value of the accelerator position sensor 43, the crank position sensor 51, or the air flow meter 44.
[0067]
  When it is determined that the operating state of the internal combustion engine 1 is in the low / medium load region, the CPU 401 controls the throttle actuator 40 so as to keep the opening of the throttle valve 39 at the fully open position. Then, so-called non-throttle control is executed to control the intake side drive circuit 30a and the exhaust side drive circuit 31a so that the intake air amount of the internal combustion engine 1 becomes a desired amount. As described above, the CPU 401 executes the non-throttle control, and thus according to the present invention.Non-throttle control execution meansIs realized.
[0068]
  When it is determined that the operation state of the internal combustion engine 1 is in the high load operation region, the CPU 401 sets the opening of the throttle valve 39 to an opening corresponding to the output signal value (accelerator opening) of the accelerator position sensor 43. Accordingly, the throttle actuator 40 is controlled, and the intake side drive circuit 30a and the exhaust side drive circuit 31a are controlled so that the torque of the internal combustion engine 1 becomes a desired target torque.
[0069]
  When it is determined that the operation state of the internal combustion engine 1 is in the idle operation region, the CPU 401 secures an intake air amount necessary for the actual rotational speed of the internal combustion engine 1 to converge to a desired target rotational speed. Therefore, so-called idle speed control (ISC) feedback control is performed to control the opening degree of the throttle valve 39.
[0070]
  Next, the CPU 401 normally controls the electromagnetic valve 67 to a fully closed state when purging the evaporated fuel. When the evaporated fuel in the fuel tank 60 increases in this state and the pressure in the fuel tank 60 exceeds the first predetermined value, the positive pressure valve of the tank internal pressure control valve 63 is opened, and the evaporated fuel passage 62 is in a conductive state. It becomes. When the evaporated fuel passage 62 becomes conductive, the evaporated fuel in the fuel tank 60 flows into the charcoal canister 61 through the evaporated fuel passage 62 and is once adsorbed by an adsorbent such as activated carbon built in the charcoal canister 61. .
[0071]
  Further, the CPU 401 determines whether or not a predetermined condition is established. As this predetermined condition, an evaporative fuel purge execution condition can be exemplified. As this purge execution condition, the fuel in the charcoal canister 61 or the evaporative fuel passage 62 whose pressure in the fuel tank 60 is equal to or higher than a predetermined value. The vehicle from the time when the previous purge is executed, the concentration is equal to or higher than the predetermined concentration, the weight of the charcoal canister 61 is equal to or higher than the predetermined value, and the elapsed time from the time when the previous purge is executed is longer than the predetermined time. For example, the driving distance of the internal combustion engine 1 in a situation where the traveling distance is equal to or longer than a predetermined distance or the outside air temperature is equal to or higher than a predetermined temperature can be exemplified.
[0072]
  When the CPU 401 determines that the purge execution condition is satisfied, the pressure of the fuel tank 60, the fuel concentration in the charcoal canister 61, and the operating state of the internal combustion engine 1 (engine speed, fuel injection amount, intake air amount). ) As a parameter, the amount of evaporated fuel to be purged (required evaporated fuel amount) is determined, and then the duty ratio (required duty ratio) for controlling the electromagnetic valve 67 is specified based on the required amount of evaporated fuel.
[0073]
  The CPU 401 applies a pulse signal corresponding to the required duty ratio to the electromagnetic valve 67 and corrects the fuel injection amount to be reduced based on the required evaporated fuel amount. When a pulse signal is applied from the CPU 401 to the electromagnetic valve 67, the negative pressure introduction passage 65 is turned on, and the purge passage 66 is turned on accordingly.
[0074]
  In this case, the pressure at the atmosphere opening end of the atmosphere introduction passage 64 upstream of the purge passage 66 becomes atmospheric pressure, and the inside of the intake pipe 35 downstream of the purge passage 66 downstream of the throttle valve 39 is negative due to the generation of intake pipe negative pressure. Due to the pressure, a pressure difference is generated between the upstream and downstream of the purge passage 49.
[0075]
  Due to the pressure difference described above, the atmosphere flows from the atmosphere open end of the purge passage 66 into the purge passage 66, and then the atmosphere in the purge passage 66 is guided into the intake pipe 35 downstream of the throttle valve 39. That is, in the purge passage 66, an atmospheric flow that flows through the charcoal canister 61 is generated.
[0076]
  As a result, the evaporated fuel adsorbed by the adsorbent in the charcoal canister 61 is desorbed from the adsorbent in response to the atmospheric flow as described above, and is introduced into the intake pipe 35 downstream of the throttle valve 39 together with the atmospheric air. . Thus, the evaporated fuel (purge gas) introduced into the intake pipe 35 is introduced into the combustion chamber 24 while being mixed with fresh air flowing from the upstream side of the intake pipe 35 and fuel injected from the fuel injection valve 32. Burned and processed.
[0077]
  By the way, when the operation state of the internal combustion engine 1 is in the low / medium load operation region and the non-throttle control is being executed, the throttle valve 39 is substantially fully opened, and therefore the intake pipe 35 downstream of the throttle valve 39. Since the intake pipe negative pressure is hardly generated in the inside and the pressure difference between the upstream and the downstream of the purge passage 66 becomes very small, it is difficult to purge a desired amount of evaporated fuel.
[0078]
  Therefore, in the present embodiment, the CPU 401 controls the throttle actuator 40 to close the throttle valve 39 by a predetermined amount when the evaporated fuel purge execution condition is satisfied when the internal combustion engine 1 is under non-throttle control. As a result, an intake pipe negative pressure is generated in the intake pipe 35 downstream of the throttle valve 39, thereby generating a pressure difference between the upstream and downstream of the purge passage 66. As described above, the CPU 401 controls the throttle valve 39, thereby realizing the throttle valve control means according to the present invention. The predetermined amount described above is preferably set so that the necessary minimum negative pressure is secured by using the required amount of evaporated fuel, engine speed, etc. as parameters. This is because if the throttle valve 39 is excessively closed, the pumping loss of intake air becomes unnecessarily large and the fuel consumption may increase.
[0079]
  Further, simply closing the throttle valve 39 by a predetermined amount may reduce the intake air amount of the internal combustion engine 1 and induce torque fluctuation. In this embodiment, the internal combustion engine 1 is subjected to non-throttle control. When the purge control is executed under the circumstances, the CPU 401 controls the throttle actuator 40 to close the throttle valve 39 by a predetermined amount, and at the same time, sets the opening / closing timing of the intake valve 28 and the exhaust valve 29 to each cylinder. The intake side drive circuit 30a and the exhaust side drive circuit 31a are controlled so as to change to the timing at which the intake efficiency of 21 is increased. In this case, even if the throttle valve 39 is closed by a predetermined amount so as to generate a pressure difference between the upstream and downstream of the purge passage 66, the intake air amount of each cylinder 21 does not decrease, and torque fluctuation or the like. The trouble will not occur. As described above, the CPU 401 controls the intake-side electromagnetic drive mechanism 30 and the exhaust-side electromagnetic drive mechanism 31 to implement the valve mechanism control means according to the present invention.
[0080]
  Hereinafter, the purge control according to the present embodiment will be specifically described.
  When executing the purge control, the CPU 4014A purge control routine as shown in FIG. This purge control routine is a routine that is stored in the ROM 402 in advance, and is a routine that is repeatedly executed by the CPU 401 every predetermined time (for example, every time the crank position sensor 51 outputs a pulse signal).
[0081]
  In the purge control routine, the CPU 401 first determines in step S1201 whether or not a purge execution condition for evaporated fuel is satisfied.
[0082]
  If the CPU 401 determines in S1201 that the evaporated fuel purge execution condition is satisfied, the CPU 401 proceeds to S1202 and determines whether or not the operating state of the internal combustion engine 1 is in the non-throttle control execution region.
[0083]
  If it is determined in S1202 that the operating state of the internal combustion engine 1 is not in the non-throttle control execution region, the CPU 401 proceeds to S1211 and executes normal purge control.
[0084]
  On the other hand, if it is determined in S1202 that the operating state of the internal combustion engine 1 is in the non-throttle control execution region, the CPU 401 proceeds to S1203 and uses the pressure in the fuel tank 60 and the fuel concentration in the charcoal canister 61 as parameters. The amount of evaporated fuel to be purged (required evaporated fuel amount) is calculated.
[0085]
  In S1204, the CPU 401 calculates the minimum intake pipe negative pressure (target intake pipe negative pressure) necessary for purging the evaporated fuel of the required evaporated fuel amount calculated in S1204.
[0086]
  In S1205, the CPU 401 determines the target throttle opening of the throttle valve 39 based on the target intake pipe negative pressure calculated in S1204.
[0087]
  In S1206, the CPU 401 receives the output signal of the air flow meter 44, detects the intake air amount at the present time, and sets the detected intake air amount as the target intake air amount.
[0088]
  In step S1207, the CPU 401 determines target opening / closing timings of the intake valve 28 and the exhaust valve 29 using the target throttle opening and the target intake air amount as parameters.
[0089]
  In S1208, the CPU 401 controls the throttle actuator 40 to gradually change the actual opening of the throttle valve 39 to the target throttle opening determined in S1205, and simultaneously opens and closes the intake valve 28 and the exhaust valve 29. The intake side drive circuit 30a and the exhaust side drive circuit 31a are controlled so as to be gradually changed until the target opening / closing timing determined in S1207.
[0090]
  In step S1209, the CPU 401 determines whether or not the actual intake pipe negative pressure has decreased to the required intake pipe negative pressure. Here, the actual intake pipe negative pressure may be estimated using the opening degree of the throttle valve 39 (target throttle opening degree), the output signal value of the air flow meter 44 (intake air amount), etc. as a parameter. It may be directly detected by providing a pressure sensor for detecting the pressure in the tank 34.
[0091]
  If it is determined in S1209 that the actual intake pipe negative pressure has not decreased to the required intake pipe negative pressure, the CPU 401 once ends the execution of this routine. If the CPU 401 determines that the actual intake pipe negative pressure has decreased to the required intake pipe negative pressure in S1209 when this routine is executed again after a predetermined time has elapsed, the process proceeds to S1210.
[0092]
  In step S1210, the CPU 401 executes purge of evaporated fuel. That is, the CPU 401 specifies a duty ratio (required duty ratio) for controlling the electromagnetic valve 67 based on the required evaporated fuel amount calculated in S1203, and applies a pulse signal corresponding to the required duty ratio to the electromagnetic valve 67. At the same time, the fuel injection amount is reduced based on the required evaporated fuel amount. In this case, when the throttle valve 39 is closed by a predetermined amount, the amount of intake air passing through the throttle valve 39 is reduced, and intake pipe negative pressure is generated in the intake pipe 35 downstream of the throttle valve 39. As a result, the upstream of the purge passage 66 becomes atmospheric pressure, and the intake pipe 35 downstream of the throttle valve 39, which is downstream of the purge passage 66, has a negative pressure. Occurs.
[0093]
  Due to the pressure difference described above, the atmosphere flows from the atmosphere open end of the purge passage 66 into the purge passage 66, and then the atmosphere in the purge passage 66 is guided into the intake pipe 35 downstream of the throttle valve 39. That is, in the purge passage 66, an atmospheric flow that flows through the charcoal canister 61 is generated. When an atmospheric flow flowing through the charcoal canister 61 is generated, the evaporated fuel adsorbed by the adsorbent in the charcoal canister 61 is desorbed from the adsorbent by receiving the atmospheric flow, and the intake pipe downstream of the throttle valve 39 together with the air. 35. The evaporated fuel (purge gas) introduced into the intake pipe 35 is introduced into the combustion chamber 24 while being mixed with fresh air flowing from the upstream side of the intake pipe 35 and fuel injected from the fuel injection valve 32, and is burned. It is processed.
[0094]
  On the other hand, when the opening degree of the throttle valve 39 is changed to the target throttle opening degree, the opening / closing timings of the intake valve 28 and the exhaust valve 29 correspond to the opening degree of the throttle valve 39 and the intake of each cylinder 21. Since the timing is changed to a timing at which the efficiency increases, the intake air amount of each cylinder 21 does not decrease, and as a result, the torque fluctuation of the internal combustion engine 1 does not occur.
[0095]
  Where4Returning to step, when the CPU 401 finishes executing the processing of S1210 described above, the execution of this routine is once ended. The CPU 401 executes this routine again after a predetermined time has elapsed from the time when the execution of this routine is completed. At this time, if the purge of the required evaporated fuel amount is completed, the purge execution condition is satisfied in S1201. If it is not determined, the process proceeds to S1212.
[0096]
  In step S1212, the CPU 401 closes the electromagnetic valve 67 so as to end the purge of the evaporated fuel.
[0097]
  In S1213, the CPU 401 controls the throttle actuator 40 to return the opening of the throttle valve 39 to the normal opening, and drives the intake side to return the opening / closing timing of the intake valve 28 and the exhaust valve 29 to the normal opening / closing timing. The circuit 30a and the exhaust side drive circuit 31a are controlled.
[0098]
  Thus, when the CPU 401 executes the purge control routine, the throttle valve control means and the valve mechanism control means according to the present invention are realized. Therefore, according to the internal combustion engine having the variable valve mechanism according to the present embodiment, when the evaporative fuel purge execution condition is satisfied when the operation state of the internal combustion engine 1 is in the non-throttle control execution region, the internal combustion engine 1 The intake pipe negative pressure can be generated without changing the amount of intake air, and the purge of the evaporated fuel can be executed without inducing torque fluctuation or the like of the internal combustion engine 1.
[0099]
  In the present embodiment, as the variable valve mechanism according to the present invention, an electromagnetically driven valve mechanism in which both the intake valve and the exhaust valve are driven to open and close by electromagnetic force is taken as an example. Only one of the exhaust valve and the electromagnetically driven valve mechanism may be configured.
[0100]
  Further, in this embodiment, as the variable valve mechanism according to the present invention, an electromagnetically driven valve mechanism that opens and closes the intake valve and the exhaust valve by electromagnetic force is taken as an example, but hydraulic pressure is used instead of electromagnetic force. In an internal combustion engine having a hydraulically driven variable valve mechanism and a camshaft that opens and closes an intake / exhaust valve using the rotational force of the crankshaft, the intake valve and the exhaust are changed by changing the rotational phase of the camshaft with respect to the crankshaft. A mechanical variable valve mechanism that adjusts the opening / closing timing of the valve or a variable valve mechanism that is a combination of these variable valve mechanisms may be used.
[0101]
  In the present embodiment, the configuration in which the downstream end of the purge passage 66 is connected to the intake pipe 35 downstream of the throttle valve 39 has been described.5The figure6As shown in FIG. 4, the purge passage 66 is branched into four branch pipes 66A, 66B, 66C, 66D in the middle of the purge passage 66, and the branch pipes 66A, 66B, 66C, 66D are in the intake port 26 of each cylinder 21. You may make it form so that it may be connected to.
[0102]
  Since the internal combustion engine 1 in the present embodiment has two intake ports 26 per cylinder, each branch pipe 66A, 66B, 66C, 66D of the purge passage 66 has two intake ports of each cylinder 21. The branch pipes 66A, 66B, 66C, 66D may be further branched into two branch pipes to both the two intake ports 26 of each cylinder 21. You may make it connect. Further, the purge passage 66 may be branched into eight branch pipes, and the branch pipes and the intake ports 26 of the internal combustion engine 1 may be connected on a one-to-one basis.
[0103]
  Next, an electromagnetic valve 67 for opening and closing the flow path in the purge passage 66 is shown in FIG.6In the purge passage 66, one may be provided at a location upstream of the portion branched into four branch pipes 66A, 66B, 66C, 66D, or FIG.7As shown in FIG. 6, the solenoid valves 67A, 67B, 67C, and 67D may be provided independently for the individual branch pipes 66A, 66B, 66C, and 66D. In that case, it is preferable that each solenoid valve 67A, 67B, 67C, 67D is disposed at a position close to the intake port 26 in each branch pipe 66A, 66B, 66C, 66D. This is because when the distance from the solenoid valves 67A, 67B, 67C, 67D to the intake port 26 becomes longer, the response delay time from when the solenoid valve 67 is opened until when the evaporated fuel actually reaches the intake port 26 This is because purge control (for example, fuel injection amount reduction correction) needs to be executed in consideration of the response delay time, and the purge control becomes complicated.
[0104]
  Each branch pipe 66A, 66B, 66C, 66D5As shown in FIG. 2, it is preferable that the air intake port 26 is formed so as to face the intake port 26 from above. This is to prevent clogging in the branch pipes 66A, 66B, 66C, 66D due to the liquefied fuel or water adhering to the branch pipes 66A, 66B, 66C, 66D.
[0105]
  As described above, when the downstream end of the purge passage 66 is connected to the intake port 26 of the internal combustion engine 1, the cross-sectional area of the intake port 26 is smaller than the cross-sectional area of the intake pipe 35 and flows in the intake port 26. Since the flow velocity of the intake air becomes faster than the flow velocity of the intake air flowing through the intake pipe 35, the evaporated fuel in the purge passage 66 can be drawn into the intake port 26 using the flow velocity of the intake air. As a result, when the operating state of the internal combustion engine 1 is in the non-throttle control execution region, it is possible to purge the evaporated fuel with almost no change in the throttle opening.
[0106]
【The invention's effect】
  According to the present invention,Even when the internal combustion engine is under non-throttle operation control, it becomes necessary to operate the evaporated fuel recirculation mechanism.Without changing the intake air volume of the internal combustion engineIt is possible to generate intake pipe negative pressure related to the operation of the evaporated fuel recirculation mechanism, and as a result,While preventing torque fluctuations in internal combustion enginesThe evaporated fuel recirculation mechanism can reliably recirculate the evaporated fuel generated in the fuel tank to the intake passage.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine having a variable valve mechanism in an embodiment.
FIG. 2 is a diagram showing an internal configuration of an intake-side electromagnetic drive mechanism in the embodiment
FIG. 3 is a block diagram showing an internal configuration of the ECU in the embodiment
FIG. 4 is a flowchart showing a purge control routine in the embodiment.
FIG. 5 is a view showing another embodiment in the vicinity of the intake port in the internal combustion engine.
FIG. 6 is a view showing another embodiment of the purge passage (1)
FIG. 7 is a view (2) showing another embodiment of the purge passage.
[Explanation of symbols]
    1 ... Internal combustion engine
    20 ... ECU
    26 ... Intake port
    27 ... Exhaust port
    28 ... Intake valve
    29 ... Exhaust valve
    30 ... Intake side electromagnetic drive mechanism
    30a ... Intake side drive circuit
    31 ... Exhaust side electromagnetic drive mechanism
    31a..Exhaust side drive circuit
    33 ... Intake branch pipe
    34 ... Surge tank
    35 ... Intake pipe
    36 ... Air cleaner box
    39 ... Throttle valve
    40 ... Throttle actuator
    41 ... Throttle position sensor
    42 Accelerator pedal
    43 Accelerator position sensor
    60 ... Fuel tank
    61 ... Charcoal canister
    62 ... Evaporative fuel passage
    63 ... Tank internal pressure control valve
    64 ... Air introduction passage
    65 ... Negative pressure introduction passage
    66 ... Purge passage

Claims (2)

An internal combustion engine having a variable valve mechanism capable of adjusting the opening and closing timing of an intake valve and an exhaust valve of the internal combustion engine,
A throttle valve for adjusting the flow rate of the intake air flowing in the intake passage;
An evaporative fuel recirculation mechanism for recirculating evaporative fuel generated in a fuel tank to the intake passage downstream of the throttle valve;
Non-throttle operation control execution means for executing non-throttle operation control when the operation state of the internal combustion engine is in a predetermined operation region;
Throttle valve control means for closing the throttle valve by a predetermined amount when it is necessary to operate the evaporated fuel recirculation mechanism during execution of the non-throttle operation control;
A valve that controls the variable valve mechanism so that the intake efficiency of each cylinder is increased so as to suppress a change in the intake air amount of the internal combustion engine when the throttle valve control means closes the throttle valve by a predetermined amount. Mechanism control means;
A required evaporated fuel amount calculating means for calculating a required evaporated fuel amount that is an evaporated fuel amount to be returned to the intake passage when the evaporated fuel recirculation mechanism is operated;
Target intake pipe negative pressure calculating means for calculating a target intake pipe negative pressure, which is a minimum intake pipe negative pressure required for returning the evaporated fuel of the required evaporated fuel amount to the intake passage;
Target throttle opening determining means for determining a target throttle opening of the throttle valve based on the target intake pipe negative pressure;
Target intake air amount setting means for detecting an intake air amount at the time of operating the evaporative fuel recirculation mechanism and setting the detected intake air amount as a target intake air amount;
Using target throttle valve opening and target intake air amount as parameters, target open / close timing determining means for determining target open / close timing of the intake valve and exhaust valve , and
When it becomes necessary to operate the evaporated fuel recirculation mechanism during execution of the non-throttle operation control, the throttle valve control means gradually closes the throttle valve opening to the target throttle opening, At the same time, the valve mechanism control means controls the variable valve mechanism to gradually change the opening / closing timing of the intake valve and the exhaust valve until the target opening / closing timing. organ. The internal combustion engine having a variable valve mechanism according to claim 1, wherein the variable valve mechanism drives the intake valve and / or the exhaust valve using electromagnetic force.

Images